Chpts. 1-2 Flashcards
What differentiates drug actions and drug effects?
Drug action refers to molecular changes produced by a drug when it binds to a target site or receptor. Drug effects are alterations or changes as a result of these molecular changes.
What are specific and nonspecific drug effects?
Specific drug effects are based on physical interactions of a drug with its target site. Nonspecific drug effects are based on unique characteristics of the individual, such as mood and expectations.
What are the major factors influencing drug absorption?
Factors influencing absorption include route of administration, salt form of the drug, lipid solubility, ionization, drug concentration, gender & size, stomach emptying time, and physical activity.
What factors influence drug distribution and metabolism?
Factors include lipid solubility, amount of lipid in tissue, blood flow, concentration gradient, size, and gender.
What factors influence drug excretion?
Factors include kidney function, protein binding, pH of urine, and urine flow.
What are the advantages and disadvantages of oral drug administration?
Advantages: safe; self-administered; no needle-related complications. Disadvantages: slow and highly variable absorption; subject to first-pass metabolism; less predictable blood levels.
What are the advantages and disadvantages of intravenous drug administration?
Advantages: most rapid; most accurate blood concentration. Disadvantages: overdose danger; cannot be reversed; requires needles and medical technique.
What are the advantages and disadvantages of intramuscular drug administration?
Advantages: slow and even absorption. Disadvantages: localized irritation at site of injection; needs sterile equipment.
What are the advantages and disadvantages of subcutaneous drug administration?
Advantages: slow and prolonged absorption. Disadvantages: variable absorption depending on blood flow.
What are the advantages and disadvantages of inhalation drug administration?
Advantages: large absorption surface; very rapid onset; no needle needed. Disadvantages: irritation of nasal passages; inhaled small particles may damage lungs.
What are the advantages and disadvantages of topical drug administration?
Advantages: localized action and effects; easy to self-administer. Disadvantages: may be absorbed into general circulation.
What are the advantages and disadvantages of transdermal drug administration?
Advantages: controlled and prolonged absorption. Disadvantages: local irritation; useful only for lipid-soluble drugs.
What are the advantages and disadvantages of epidural drug administration?
Advantages: bypasses blood-brain barrier; very rapid effect on CNS. Disadvantages: not reversible; needs trained anesthesiologist; possible nerve damage.
What are the advantages and disadvantages of intranasal drug administration?
Advantages: ease of use; local or systemic effects; very rapid; no first-pass metabolism. Disadvantages: not all drugs can be atomized; potential irritation of nasal mucosa.
What is the blood-brain barrier?
The blood-brain barrier (BBB) is the separation between brain capillaries and the brain, limiting the movement of ionized molecules while allowing lipid-soluble drugs to enter.
How do affinity and intrinsic activity differ for agonists and antagonists?
Affinity refers to how strongly a drug binds to a receptor. Intrinsic refers to a drug’s ability to activate the receptor and produce a biological response. Agonists have high intrinsic activity as they activate the receptor, while antagonists have no intrinsic activity and block agonists.
What are the differences between full, partial, indirect, and inverse agonists?
Full agonists produce the maximum response by fully activating the receptor. Partial agonists have some effect. Indirect agonists increase neurotransmitter levels without binding to the receptor. Inverse agonists releases an action opposite to that of an agonist.
How do potency and efficacy of a drug differ? How are they similar?
Potency is the absolute amount of drug necessary to produce a specific effect, while efficacy measures the maximum response a drug can produce. Both relate to how a drug interacts with receptors to produce effects.
What is the therapeutic index and why is it important?
The therapeutic index (TI) measures a drug’s safety margin, calculated as TI = LD50/ED50. A higher TI indicates a safer drug.
How do competitive and noncompetitive antagonists differ? How are they similar?
Competitive antagonists bind directly to the same receptor site as the agonist, reducing potency but not max efficacy. Noncompetitive antagonists bind to a different site, reducing max efficacy but not potency. Both block/reduce the effects of agonists, both bind to receptors
What is potentiation and how does it differ from an additive effect?
Potentiation occurs when one drug enhances the effect of another without having an effect on its own. Additive effects occur when the combined effect equals the sum of individual effects.
What do psychoactive drugs do in the brain?
Psychoactive drugs modify brain function to exert changes in behavior and mental processes by altering chemical activity within the nervous system.
What are the three parts of a neuron?
The three parts are the soma (cell body), dendrites (projections that receive information), and axon (extension that conducts electrical signals).
What is epigenetics?
Epigenetics refers to the control of gene expression by chromosome modifications that do not affect the DNA code.
How do local potentials differ from action potentials? How are they similar?
Local potentials are small, transient changes in membrane potential, while action potentials are large, uniform changes that maintain strength over long distances. Both involve ion movement & both depend on changes in membrane potential
How do drugs and toxins alter conduction?
They target ion channels, neurotransmitters, and enzymes, enhancing, blocking, or disrupting normal electrical activity.
What are the behavioral effects of the sympathetic nervous system?
The sympathetic nervous system mediates the ‘fight-or-flight’ response, leading to alertness, anxiety, aggression, increased energy, agitation, and reduced appetite.
What are the behavioral effects of the parasympathetic nervous system?
The parasympathetic nervous system promotes ‘rest and digest’ functions, leading to relaxation, drowsiness, contentment, improved digestion, and reduced stress.
Why is damage to the hindbrain detrimental?
The hindbrain controls vital life functions necessary for survival, including breathing and heart rate.
What behavioral effects of alcohol are seen from its actions on the cerebellum?
Alcohol can cause poor balance, lack of coordination, slurred speech, delayed reaction time, dizziness, and vertigo.
What are the general responsibilities of forebrain regions, including subcortical areas?
Subcortical includes the thalamus, hypothalamus, amygdala, and hippocampus
What are the general responsibilities of forebrain regions, including cortical areas?
Cortical includes the frontal lobe (decision-making, impulse control, planning, & problem-solving), parietal lobe (sensory processing), occipital lobe (vision), and temporal (hearing, lang. comp. & memory)
What behavioral effects of alcohol are seen from its actions within limbic areas?
Emotional instability, impaired memory, and increased impulsivity.
